The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
Most residential and light-commercial buildings have concrete footer and foundations which are cast in place on site before the construction of the building begins. The purpose of the footer is to provide a solid base for the building to prevent structural movement and other damage. These cast-in-place concrete footers are traditionally poured in place with the use of wood forms which are typically 2′×8′ boards. As a practical matter, the conventional wood 2′×8′ boards provide excellent vertical beam stiffness to facilitate proper leveling of the poured footings, and the boards are also relatively resistant to heavy impact during use.
Once the footer is poured and the concrete sets up, the lumber forms are removed and drainage pipe is installed. The drainage pipe is a critical component of the footer system because excessive water can lead to structural failure. In addition to water management, the pipe also serves to ensure water is evacuated from the area. The process of installing the lumber forms, removing the lumber forms after the concrete is set, and then installing the drainage system is time intensive for the contractor and has multiple steps resulting in safety risks and potential for mistakes to occur.
There are a few existing manufactured alternative solutions to the traditional use of lumber forms for the construction of building footers. One product utilizes an extruded polyvinyl chloride (PVC) rectangular profile pipe that serves as the concrete form and is left in place to provide foundation drainage once the building is complete. The rectangular PVC pipe greatly accelerates and simplifies the construction process and provides a great deal of beam stiffness similar to 2′×8′ lumber form. The deficiency with the rectangular PVC pipe, however, is that it is very brittle and sensitive to handling, especially in cold temperature climates. The poor impact performance limits the product's market acceptance.
A second product solution on the market is a rectangular corrugated high-density polyethylene (HDPE) pipe that serves the dual purpose for the footer form and is designed to remain in place long term to provide foundation drainage. The benefit of the rectangular corrugated HDPE pipe is the high level of impact resistance performance due to the more flexible nature of the material. The conventional rectangular corrugated HDPE pipe, however, is deficient in vertical beam stiffness, as it is significantly more flexible than the rectangular PVC pipe and the 2′×8′ lumber form. Consequently, vertical sagging can occur over the length of the pipe, thus causing the formation of uneven footings.
With traditional HDPE foundation drain pipe (as well as PVC pipe), it is common to form the pipe with an inner web to add lateral strength and resist inward deflection or distortion of the pipe. However, such internal webbing is not constructed to prevent the HDPE pipe from exhibiting undesirable sagging due to inadequate vertical beam stiffness of the product.
For the foregoing reasons, there is a significant need in the industry for a foundation drain which includes the benefits of the impact resistant HDPE pipe, yet exhibits the longitudinal beam stiffness akin to PVC pipe. It is with these goals in mind that the present invention has been developed.